Gear actuator for double clutch transmission

ABSTRACT

Disclosed herein is a gear actuator for a double clutch transmission. A power pack module is formed of a select solenoid, a shift motor, and a controller. Therefore, a wiring is omitted, so that defects pertaining to the wiring can be prevented, and the structure of the gear actuator is compact. Various parts can be used in common so that the production cost and the part management cost can be reduced.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to Korean Patent Application No(s).10-2016-0090809, filed on Jul. 18, 2016, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments of the present invention relate to a gear actuator for adouble clutch transmission, and more particularly, to a gear actuatorconfigured to perform a select and shift operation in a double clutchtransmission.

Description of the Related Art

A double clutch transmission (DCT) is a kind of automatic manualtransmission (AMT) configured to automatically perform a gearshiftoperation (select and shift operation) of a manual transmission. Toembody an independent gearshift operation of each of an odd-numberedstage and an even-numbered stage, an actuator and a controllerconfigured to control the operation of the actuator are provided foreach of the odd-numbered stage and the even-numbered stage.

FIG. 1 is a rear view illustrating a gear actuator for a DCT inaccordance with a conventional technique. FIG. 2 is a bottom view ofFIG. 1. As shown in FIGS. 1 and 2, the conventional gear actuator for aDCT includes an odd-numbered stage select solenoid 1, an odd-numberedstage shift motor 2, an even-numbered stage select solenoid 3, aneven-numbered stage shift motor 4, a control shaft assembly 5 which ismechanically coupled to the solenoids and the motors and configured toselect and shift a lug of a shift rail, and a housing 6 in which theabove-mentioned parts are installed.

Therefore, the control shaft assembly 5 is operated by the solenoid andthe motor of each of the odd-numbered stage and the even-numbered stageso that an independent gearshift operation (select and shift) of each ofthe odd-numbered stage and the even-numbered stage can be embodied.

The solenoids 1 and 3 and the motors 2 and 4 are respectively connectedto controllers (not shown) by individual wirings 7 a, 7 b, 8 a, and 8 bto supply electric power and transmit a control signal. The individualwirings 7 a and 7 b of the solenoids 1 and 3 are integrated into onewiring, and the individual wirings 8 a and 8 b of the motors 2 and 4 areintegrated into one wiring. Each integrated wiring is coupled to thecorresponding controller (not shown) by a connector 7 c, 8 c.

However, because the wirings are coupled to the solenoids and the motorsby fusing, defective connection is frequently caused. Becauseinstallation space of the gear actuator is limited, the wirings may beexcessively bent. In this case, disconnection of the wirings may becaused by tensile stress.

Furthermore, in the conventional gear actuator for the DCT, since thelength of the solenoid is greater than that of the motor, the rearsurfaces of the solenoids and the motors are not disposed on the sameplane. The solenoids and the motors are angled to each other rather thanbeing parallel to each other, so that the operational directions thereofdiffer from each other. Therefore, it is difficult to modularize thesolenoids and the motors along with the controllers to remove thewirings. In addition, because the operational directions of thesolenoids and the motors differ from each other, they are vulnerable tovibration.

As shown in FIG. 3, in the conventional solenoid (because the selectsolenoids of the odd-numbered stage and the even-numbered stage are thesame as each other, the select solenoid of only the odd-numbered stageis illustrated), a first coil la for push and a second coil 1 b for pullare controlled in an on/off manner such that a single coil takescomplete charge of a push or pull operation. Thus, to generate asufficient amount of magnetic force, the coil must be relatively long.Hence, there is no alternative but for the entire length of the solenoidto increase. In the drawings, reference numeral 1 c denotes a plungerwhich is moved in a push or pull direction when a magnetic field isformed around the coil. Reference numeral 1 d denotes a select rod whichintegrally moves with the plunger 1 c to transmit push or pull operatingforce to a connection part (select lever).

Furthermore, the solenoid and motor of the odd-numbered stage and thesolenoid and motor of the even-numbered stage are disposed in separateregions, rather than being disposed in the same region. This structuremakes modularization difficult.

As such, because an electrically-powered unit (the select solenoid andthe shift motor) and a controller are not modularized, a plurality ofwirings must be used. Thus, the above-mentioned wiring-related problemis caused. In addition, due to a large number of parts, the number ofmanufacturing processes is increased, whereby there is a problem ofdegradation of assemblability and productivity.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a gear actuator for adouble clutch transmission in which an electrically-powered unit and acontroller are modularized so that there is no need of a separatewiring, whereby the problems of disconnection or defective connection ofwirings are solved, a compact structure is provided, and thanks to areduction in the number of parts, not only can the assemblability andproductivity be increased but the part production and management costscan also be reduced.

Other objects and advantages of the present invention can be understoodby the following description, and become apparent with reference to theembodiments of the present invention. Also, it is obvious to thoseskilled in the art to which the present invention pertains that theobjects and advantages of the present invention can be realized by themeans as claimed and combinations thereof.

In accordance with one aspect of the present invention, a gear actuatorfor a double clutch transmission may include: an odd-numbered stagepower pack module and an even-numbered stage power pack module eachcomprising a select solenoid, a shift motor, and a controller directlyattached to the select solenoid and the shift motor; a body housing inwhich the odd-numbered stage power pack module and the even-numberedstage power pack module are installed; and a control shaft assemblycoupled to the power pack modules in the body housing and configured totransmit a select and shift operation force to a lug of a shift rail.

The select solenoid and the shift motor of each of the power packmodules may be installed parallel to each other.

Respective rear ends of the select solenoid and the shift motor of eachof the power pack modules may be disposed on the same plane.

The select solenoid and the shift motor of the odd-numbered stage powerpack module and the select solenoid and the shift motor of theeven-numbered stage power pack module may be axisymmetrically disposed.

The controller may be applied in common to the odd-numbered stage powerpack module and the even-numbered stage power pack module.

The select solenoid may include a single coil for forming a magneticfield, wherein the coil may be divided into two parts spaced apart fromeach other, and the two parts may have respective opposite windingdirections.

The select solenoid may include a plunger provided in an inner hole of abobbin around which the coil is wound, and the plunger may be apermanent magnet.

A direction in which current is supplied to the coil may be switched bythe corresponding controller.

The control shaft assembly may include an odd-numbered stage controlshaft and an even-numbered stage control shaft which are coupled to eachother in a double-pipe structure. A shift finger member may be fixed toeach of the control shafts, and the shift finger member of each of theodd-numbered stage and the even-numbered stage may be moved in avertical direction by one end of a select lever configured to be rotatedby the corresponding select solenoid and be rotated in a circumferentialdirection by a nut of a lead screw configured to be operated by thecorresponding shift motor.

A pair of select guides facing each other in the vertical direction mayprotrude from an outer circumferential surface of the shift fingermember of each of the odd-numbered stage and the even-numbered stage,and the end of the select lever may be inserted between and stopped bythe select guides.

A pair of shift guides facing each other in a front-rear direction mayprotrude from an outer circumferential surface of the nut of the leadscrew, and a shift finger protruding from the select guide may beinserted between and stopped by the shift guides.

The select guide and the shift finger of each of the odd-numbered stageand the even-numbered stage may protrude toward a mechanical partcoupled to the corresponding power pack module.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a rear view illustrating a gear actuator in accordance with aconventional technique;

FIG. 2 is a bottom view of FIG. 1;

FIG. 3 is view illustrating the configuration of a select solenoid usedin the conventional gear actuator;

FIG. 4 is a rear perspective view illustrating a gear actuator inaccordance with the present invention;

FIG. 5 is a rear view of FIG. 4;

FIG. 6 is a bottom view of FIG. 5;

FIG. 7 is view illustrating the configuration of a select solenoid usedin the gear actuator in accordance with the present invention;

FIG. 8 is a front perspective view of FIG. 4 from which a body housinghas been removed to illustrate the structure of a mechanical part; and

FIG. 9 is an assembled view of a select lever, a select guide member,and a lead screw nut in accordance with the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to various embodiments of thepresent invention, specific examples of which are illustrated in theaccompanying drawings and described below, since the embodiments of thepresent invention may be variously modified in many different forms.However, this is not intended to limit the present invention toparticular modes of practice, and it is to be appreciated that allchanges, equivalents, and substitutes that do not depart from the spiritand technical scope of the present invention are encompassed in thepresent invention. The size of each element, the thickness of linesindicating the element, etc. may be exaggerated for the purpose ofclarity and convenience of description

The terms and words used for elements in the description of the presentinvention are determined based on the functions of the elements in thepresent invention. The terms and words may be changed depending on theintention or custom of users or operators, so that they must be definedbased on the whole content of the present specification.

Hereinafter, an embodiment of the present invention will be described indetail with reference to the attached drawings.

As shown in FIGS. 4 to 6, a gear actuator for a double clutchtransmission in accordance with the present invention includes: anodd-numbered stage power pack module 10 and an even-numbered stage powerpack module 20 in which controllers 13 and 23 are directly attached torespective select solenoids 11 and 21 and respective shift motors 12 and22 of an odd-numbered stage and an even-numbered stage; a body housing30 in which the odd-numbered stage power pack module 10 and theeven-numbered stage power pack module 20 are installed; and a controlshaft assembly 40 which is coupled to the power pack modules 10 and 20in the body housing 30 and configured to select and shift a lug of ashift rail.

In the odd-numbered stage power pack module 10 and the even-numberedstage power pack module 20, the respective select solenoids 11 and 21and the respective shift motors 12 and 22 of the odd-numbered stage andthe even-numbered stage are installed in power pack housings 15 and 25.The respective controllers 13 and 23 of the odd-numbered stage and theeven-numbered stage are mounted to rear surfaces of the power packhousings 15 and 25. Connectors 14 and 24 are mounted to the respectivecontrollers 13 and 23 to embody wiring connection for transmitting agear shift knob manipulation signal of a driver to the controllers 13and 23.

As described above, in the gear actuator in accordance with the presentinvention, an electrically-powered unit (the select solenoid and theshift motor) and the controller of each of the odd-numbered stage andthe even-numbered stage are modularized into a single power pack.

In each of the power pack modules 10 and 20, the select solenoid 11, 21and the shift motor 12, 22 are installed in the power pack housing 15,25 such that central axes thereof are parallel to each other.

Furthermore, the select solenoid 11, 21 has a reduced length and thus isinstalled such that rear surfaces (rear ends) of the select solenoid 11,21 and the shift motor 12, 22 are disposed on the same plane.

Therefore, in each power pack module 10, 20, the controller 13, 23 canbe directly attached to the rear surfaces (rear ends) of the selectsolenoid 11, 21 and the shift motor 12, 22. In other words, powerterminals and signal terminals of the select solenoid 11, 21 and theshift motor 12, 22 can be directly connected to a power terminal and asignal terminal of the controller 13, 23.

Not only the control shaft assembly 40 but also mechanical elementsconfigured to couple the control shaft assembly 40 to the selectsolenoids 11 and 21 and the shift motors 12 and 22 are installed in thebody housing 30. Hence, it is not preferable that the installationpositions of the select solenoids 11 and 21 be in the body housing 30 toalign the rear ends of the select solenoids 11 and 21 and the shiftmotors 12 and 22 with each other.

Therefore, in the present invention, the rear ends of the selectsolenoid 11, 21 and the shift motor 12, 22 are aligned with each otherby reducing the length of the select solenoid 11, 21. To achieve theforegoing purpose, as shown in FIG. 7 (because the select solenoids ofthe odd-numbered stage and the even-numbered stage are the same as eachother, the select solenoid of only the odd-numbered stage isillustrated), the select solenoid 11 includes: a bobbin 11 a; cores 11ba and 11 bb which are provided in respective opposite ends of an innerhole of the bobbin 11 a and configured to concentrate magnetic flux; aplunger 11 c installed in the inner hole of the bobbin 11 a so as to bemovable in opposite directions (push and pull directions); a select rod11 d which is inserted into a through hole of the plunger 11 c and fixedto the plunger 11 c so that the select rod 11 d moves along with theplunger 11 c; and a coil 11 e wound around an outer circumferentialsurface of the bobbin 11 a. In an embodiment, the coil 11 e may bedivided into two parts spaced apart from each other, and the two partsof the coil 11 e are wound in directions opposite to each other. Forexample, in the case where the coil disposed at a first side is wound ina clockwise direction when viewed from the arrow A, the coil connectedtherefrom and disposed at a second side is wound in a counterclockwisedirection. The plunger 11 c is a permanent magnet and has oppositepolarities on the respective opposite ends thereof.

The select solenoid 11 is configured such that the positions of theplunger 11 c and the select rod 11 d are controlled to a push positionor a pull position (between two positions) by switching the direction ofthe supply of current (converting the current supply direction to theopposite direction). The switching of the current supply direction canbe embodied by the controller 13, 23 that is directly attached to thecorresponding select solenoid 11, 21.

In the select solenoid 11, 21, when current is applied to the coil 11 e,the opposite cores 11 ba and 11 bb are magnetized to the same polaritybecause the winding directions of the two parts of the coil 11 e areopposed to each other.

Therefore, depending on the polarity direction of the plunger 11 c thatis a permanent magnet, attractive force is applied between one core andthe plunger 11 c, and repulsive force is applied between the other coreand the plunger 11 c. This state can be converted to the opposite stateby controlling the current supply direction to the opposite direction.In other words, when the current supply direction is converted to theopposite direction, the polarity of the cores disposed on the oppositesides is converted to the same opposite polarity. Thus, repulsive forceis applied between the plunger and the core disposed at the first side,and attractive force is applied between the plunger and the coredisposed at the second side.

Therefore, the plunger 11 c is moved in a direction in which it ispulled by the attractive force and pushed by the repulsive force.Thereby, the select rod 11 d fixed to the plunger 11 c is operated.

As such, because the plunger 11 c can be moved to any one of theopposite directions depending on the current supply direction, it ispossible to move the select rod 11 d in the push direction or the pulldirection. Particularly, since opposite directional forces (attractiveforce and repulsive force) are applied to the respective opposite endsof the plunger 11 c, the plunger 11 c can be further strongly moved.

In this way, although the single coil 11 e is used to move the plunger11 c, the magnetic field applied to the coil 11 e is divided into twoparts, and the two parts of the magnetic field are applied in theopposite directions, whereby the operational force of the plunger 11 ccan be markedly enhanced. Consequently, with the coil shorter than thatof the conventional technique, the same level of operational force canbe generated. Due to the reduced length of the coil 11 e, the length ofthe select solenoid 11, 21 can be reduced.

As shown in FIGS. 5 and 8, the select solenoid 11 and the shift motor 12of the odd-numbered stage, and the select solenoid 21 and the shiftmotor 22 of the even-numbered stage are disposed to form an axisymmetricstructure and, more particularly, have a rotational phase difference of180°, as shown in the drawings.

Furthermore, the select solenoids 11 and 21 and the shift motors 12 and22 are disposed with the same positional relationship in thecorresponding power pack modules 10 and 20.

In other words, the odd-numbered and even-numbered stage power packmodules 10 and 20 have the same configuration and structure, and thepower pack modules 10 and 20 that are installed in the body housing 30have only a rotational phase difference of 180° when viewed from therear view.

The odd-numbered and even-numbered stage power pack modules 10 and 20are mounted to power-pack-module mounting parts 31 and 32 formed on therear surface of the body housing 30. The power-pack-module mountingparts 31 and 32 have the same appearances as those of the power packhousings 15 and 25 of the power pack modules 10 and 20 so that they formthe same contour when assembled with each other.

Furthermore, output ends (select rods and rotating shafts) of the selectsolenoids 11 and 21 and the shift motors 12 and 22 that protrude fromfront surfaces of the power pack housings 15 and 25 are inserted intothe body housing 30.

The control shaft assembly 40 has a double pipe structure including anodd-numbered stage control shaft 41 and an even-numbered stage controlshaft 42 into which the odd-numbered stage control shaft 41 is inserted.The inner odd-numbered stage control shaft 41 is longer than the outereven-numbered stage control shaft 42, so that opposite ends of theodd-numbered stage control shaft 41 protrude outward from opposite endsof the even-numbered stage control shaft 42. Each control shaft 41, 42is coupled at a first end thereof (based on the drawing, the upper enddisposed in the body housing 30) with a shift finger member 41 a, 42 a.A second end (based on the drawing, the lower end disposed outside thebody housing 30) of each control shaft 41, 42 is coupled with a controlfinger member 42 a, 42 b.

The coupling structure between the control shaft assembly 40 and theoutput ends of the select solenoids 11 and 21 and the shift motors 12and 22 in the body housing 30 will be described with reference to FIGS.8 and 9 (likewise, because the coupling structures of the odd-numberedstage and the even-numbered stage are the same as each other, there willbe described the case of the even-numbered stage that is clearlyillustrated in the drawings, and the coupling structure of theodd-numbered stage will be omitted).

A first end of an L-shaped select lever 51 is rotatably coupled to aselect rod 21 c of the select solenoid 21. A second end of the selectlever 51 is installed such that it can move the shift finger member 42 aof the control shaft 42 upward or downward.

Facing each other, a pair of select guides 42 aa respectively protrudefrom upper and lower ends of an outer circumferential surface of theshift finger member 42 a. The end of the select lever 51 is disposedbetween and stopped by the select guides 42 aa.

In addition, a shift finger 42 ab radially protrudes from an outercircumferential surface of one of the select guides 42 aa.

A reduction gear device 52 is coupled to a rotating shaft (not shown) ofthe shift motor 22. A screw 53 a of a lead screw 53 is coupled to anoutput end of the reduction gear device 52. A pair of shift guides 53 baprotrude toward the control shaft assembly 40 from an outercircumferential surface of a nut 53 b, which is installed in a shapeenclosing the screw 53 a. The shift guides 53 ba are provided to faceeach other in a front-rear direction (in a direction in which the nut 53b operates on the lead screw 53). The shift finger 42 ab is insertedbetween and stopped by the shift guides 53 ba.

Therefore, when the select solenoid 21 operates, the select rod 21 dmoves forward or rearward. Thereby, the select lever 51 rotates aroundthe central axis of the select lever 51 in a clockwise orcounterclockwise direction, so that a first end of the select lever 51pushes the corresponding select guide 42 aa upward or downward. Thus,the control shaft 42 along with the shift finger member 42 a is movedupward or downward. In addition, the control finger member 42 b isintegrally moved upward or downward. Consequently, a control finger 42ba is disposed in a depression of a selected one of lugs of the shiftrail.

Thereafter, when the shift motor 22 operates, the rotating force thereofis reduced in speed by the reduction gear device 52 before beingoutputted. Thus, the screw 53 a coupled to the output end of thereduction gear device 52 rotates in a normal direction or a reversedirection. Thereby, the nut 53 b is moved forward or backward along thescrew 53 a.

Therefore, the shift finger 42 ab inserted into the shift guide 53 ba ofthe nut 53 b is moved forward/backward so that the shift finger member42 a is rotated. Thereby, the control shaft 42 is rotated, and thecontrol finger member 42 b is thus rotated. Consequently, the controlfinger 42 ba of the control finger member 42 b pulls or pushes aselected lug so that the shift rail is shifted in a direction to shiftgears. In this way, the gear shift operation is performed.

In each of the odd-numbered stage shift finger member 41 a and theeven-numbered stage shift finger member 42 a, a select guide 41 aa, 42aa and a shift finger 41 ab, 42 ab protrude from an outercircumferential surface of the shift finger member 41 a, 42 a toward thecorresponding power pack module 10, 20. Therefore, the select guide 41aa, 42 aa and the shift finger 41 ab, 42 ab can be easily coupled to theselect solenoid 11, 21 and the shift motor 12, 22 of the correspondingpower pack module 10, 20.

Hereinbelow, the operation and effect of the present invention will bedescribed.

In the gear actuator according to the present invention, theodd-numbered stage power pack module 10 is formed of the odd-numberedstage select solenoid 11, the odd-numbered stage shift motor 12, and theodd-numbered stage controller 13. Likewise, the even-numbered stagepower pack module 20 is formed of the even-numbered stage selectsolenoid 21, the even-numbered stage shift motor 22, and theeven-numbered stage controller 23. As such, the elements of each of theodd-numbered stage and the even-numbered stage, in particular, theselect solenoid 11, 21 and the shift motor 12, 22 of each of theodd-numbered stage and the even-numbered stage, are disposed in the sameregion, rather than being disposed in separate regions, so as to formthe power pack module 10, 20 of each of the odd-numbered stage and theeven-numbered stage. Therefore, the gear actuator can have a compactstructure.

Furthermore, in each power pack module 10, 20, because the rear ends ofthe select solenoid 11, 21 and the shift motor 12, 22 are disposed onthe same plane, the controller 13, 23 can be directly attached to theselect solenoid 11, 21 and the shift motor 12, 22. Therefore, a wiringand a connector which are coupled from the controller 13, 23 to theselect solenoid 11, 21 and the shift motor 12, 22 can be omitted.Thereby, the problem of defect or disconnection of a connection part ofthe wiring can be solved, and the production cost can be reduced by areduction in the number of parts.

Furthermore, in the power pack housing 15, 25 of each of theodd-numbered and even-numbered stage power pack modules 10 and 20, theselect solenoid 11, 21 and the shift motor 12, 22 are installed suchthat the central axes thereof are parallel to each other. Therefore,each power pack module 10, 20 can have a compact structure, and thereare advantages in terms of a reduction in vibration of the gear actuatorbecause the operational direction of the select solenoid 11, 21 and theshift motor 12, 22 is the same as the direction in which the output endsthereof protrude.

In each select solenoid 11, 21, the single coil 11 e is divided into twoparts (coupled to each other into the single coil), the windingdirections of which are opposite to each other. Furthermore, thedirection of supply of current is switched by the correspondingcontroller 13, 23. The plunger 11 c coupled to the select rod 11 d isformed of a permanent magnet. Therefore, when current is supplied to thecoil 11 e, opposite magnetic fields are formed around the two parts ofthe coil. Thus, magnetic forces are applied to the respective oppositeends of the plunger 11 c to move the plunger 11 c in the same direction.Consequently, despite using the coil having a reduced length, asufficient amount of operational force of the select rod 11 d can begenerated. Hence, because the lengths of the select solenoids 11 and 21can be reduced, the select solenoid 11, 21 and the shift motor 12, 22 ofeach power pack module 10, 20 can be disposed on the same plane. Thus,the select solenoids 11 and 21, the shift motor 12, 22, and thecontroller 13, 23 can be modularized in such a way that the controller13, 23 is directly attached to the rear ends of the select solenoid 11,21 and the shift motor 12, 22. Furthermore, the reduction in the lengthsof the select solenoids 11 and 21 contributes to realization of thecompact structure of the gear actuator.

In addition, because the power pack can be modularized without using awiring, the structure thereof can be further simplified, and the numberof manufacturing processes is reduced, whereby ease of assembly and massproduction can be realized.

Taking into account the entirety of the odd-numbered and even-numberedstage power pack modules 10 and 20, the select solenoids 11 and 21 andthe shift motors 12 and 22 of the odd-numbered stage and theeven-numbered stage are disposed to form an axisymmetric structure. Thatis, if the select solenoid and the shift motor of one of the power packmodules are rotated around the center axis between the opposite powerpack modules, they can be symmetric with the select solenoid and theshift motor of the other power pack module. Therefore, with regard tothe configuration of the power pack modules 10 and 20, a single type ofcontroller 13, 23 can be applied to both the odd-numbered andeven-numbered stage power pack modules 10 and 20. In other words, thecontrollers 13 and 23 can be used in common.

This is applied not only to the controller but also to the power packmodule itself. In other words, the odd-numbered and even-numbered stagepower pack modules 10 and 20, which are the same as each other, areinstalled to form axisymmetric relationship and coupled to the selectand shift devices of the odd-numbered stage and the even-numbered stage,respectively. As such, the power modules can be used in common, wherebythe assemblability and marketability of the gear actuator can bemarkedly enhanced. Furthermore, the parts constituting the odd-numberedand even-numbered stage power pack modules can be used in common.Because a large number of parts can be used in common, the partproduction and management cost can be markedly reduced.

In each of the odd-numbered and even-numbered stage shift finger members41 a and 42 a of the control shaft assembly 40, the select guide 41 aa,42 aa and the shift finger 41 ab, 42 ab respectively protrude incorresponding directions. In other words, the odd-numbered stage selectguide 41 aa and the odd-numbered stage shift finger 41 ab protrudetoward mechanical parts coupled to the odd-numbered stage power packmodule 10. The even-numbered stage select guide 42 aa and theeven-numbered stage shift finger 42 ab protrude toward mechanical partscoupled to the even-numbered stage power pack module 20. Therefore, theodd-numbered stage select guide 41 aa and the odd-numbered stage shiftfinger 41 ab and the even-numbered stage select guide 42 aa and theeven-numbered stage shift finger 42 ab can be collected in respectiveopposite regions and coupled to the mechanical parts (the select leverand the reduction gear device) of the corresponding parts.

This is also one of factors making it possible to modularize the selectsolenoid 11, 21, the shift motor 12, 22, and the controller 13, 23 intoone power pack.

As described above, according to the present invention, the length of aselect solenoid is reduced, and the select solenoid and a shift motorare disposed parallel to each other so that the rear surfaces (rearends) of the select solenoid and the shift motor can be disposed on thesame plane. Hence, a controller can be directly attached to the selectsolenoid and the shift motor. In other words, an electrically-poweredunit (the select solenoid and the shift motor) and the controller can bemodularized.

As such, the electrically-powered unit along with the controller ismodularized, so that the gear actuator can have a compact structure, andthere is no need of a separate connection part such as a wiring orconnector (for connecting the electrically-powered unit with thecontroller).

Therefore, the assembly process is simple, and the number ofmanufacturing processes is reduced, whereby the assemblability and theproductivity can be enhanced, and the part management cost is reduced.

Furthermore, because there is no need of a separate wiring, the problemof disconnection or defective connection of the wiring can befundamentally solved.

In addition, since the select solenoid and the shift motor are disposedparallel to each other, the operational directions thereof correspond toeach other. Consequently, there is an advantage in that vibrations aremitigated.

The odd-numbered stage electrically-powered unit and the even-numberedstage electrically-powered unit are disposed to have an axisymmetricstructure, so that a single controller can be used in common for theodd-numbered module and the even-numbered module. As a result, the partproduction and management costs can be reduced.

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. A gear actuator for a double clutch transmission,comprising: an odd-numbered stage power pack module and an even-numberedstage power pack module each comprising a select solenoid, a shiftmotor, and a controller directly attached to the select solenoid and theshift motor; a body housing in which the odd-numbered stage power packmodule and the even-numbered stage power pack module are installed; anda control shaft assembly coupled to the power pack modules in the bodyhousing and configured to transmit a select and shift operation force toa lug of a shift rail.
 2. The gear actuator according to claim 1,wherein the select solenoid and the shift motor of each of the powerpack modules are installed parallel to each other.
 3. The gear actuatoraccording to claim 1, wherein respective rear ends of the selectsolenoid and the shift motor of each of the power pack modules aredisposed on the same plane.
 4. The gear actuator according to claim 1,wherein the select solenoid and the shift motor of the odd-numberedstage power pack module and the select solenoid and the shift motor ofthe even-numbered stage power pack module are axisymmetrically disposed.5. The gear actuator according to claim 1, wherein the controller isapplied in common to the odd-numbered stage power pack module and theeven-numbered stage power pack module.
 6. The gear actuator according toclaim 1, wherein the select solenoid comprises a single coil for forminga magnetic field, wherein the coil is divided into two parts spacedapart from each other, and the two parts have respective oppositewinding directions.
 7. The gear actuator according to claim 6, whereinthe select solenoid comprises a plunger provided in an inner hole of abobbin around which the coil is wound, and the plunger is a permanentmagnet.
 8. The gear actuator according to claim 6, wherein a directionin which current is supplied to the coil is switched by thecorresponding controller.
 9. The gear actuator according to claim 1,wherein the control shaft assembly comprises an odd-numbered stagecontrol shaft and an even-numbered stage control shaft which are coupledto each other in a double-pipe structure, a shift finger member is fixedto each of the control shafts, and the shift finger member of each ofthe odd-numbered stage and the even-numbered stage is moved in avertical direction by one end of a select lever configured to be rotatedby the corresponding select solenoid and is rotated in a circumferentialdirection by a nut of a lead screw configured to be operated by thecorresponding shift motor.
 10. The gear actuator according to claim 9,wherein a pair of select guides facing each other in the verticaldirection protrude from an outer circumferential surface of the shiftfinger member of each of the odd-numbered stage and the even-numberedstage, and the end of the select lever is inserted between and stoppedby the select guides.
 11. The gear actuator according to claim 10,wherein a pair of shift guides facing each other in a front-reardirection protrude from an outer circumferential surface of the nut ofthe lead screw, and a shift finger protruding from the select guide isinserted between and stopped by the shift guides.
 12. The gear actuatoraccording to claim 11, wherein the select guide and the shift finger ofeach of the odd-numbered stage and the even-numbered stage protrudetoward a mechanical part coupled to the corresponding power pack module.